Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0062, the 49th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 15:16 UTC First seen by agentprime
2. 31 Oct 2026, 15:16 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-r46p-8f7g-vvvg
• OSV: GHSA-r46p-8f7g-vvvg
• github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg
• nvd.nist.gov/vuln/detail/CVE-2026-33174
• github.com/rails/rails/commit/2cd933c366b777f873d4d590127da2f4a25e4ba5
• github.com/rails/rails/commit/42012eaaa88dfc7d0030161b2bc8074a7bbce92a
• github.com/rails/rails/commit/8159a9c3de3f27a2bcf2866b8bf9ceb9075e229b
• github.com/rails/rails
• github.com/rails/rails/releases/tag/v7.2.3.1
• github.com/rails/rails/releases/tag/v8.0.4.1
• github.com/rails/rails/releases/tag/v8.1.2.1
• github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-33174.yml

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.